Pump structure



w. J. HUIGENS PUMP STRUCTURE Filed Aug. 9, 1963 U l'nz/fentor: Wilfred cl Mavens May 5, 1964 United States Patent 3,131,639 PUMP STRUCTURE Wilfred J. Huigens, Clarinda, Iowa, assiguor to Lisle Corporation, Clarinda, Iowa, a corporation of Iowa Fiied Aug. 9, 1963, Ser. No. 300,974 8 Claims. (Cl. 103-50) This invention relates to a pump structure of comparatively simple and inexpensive construction adapted for the transfer of fluids from one container or the like to another container or the like.

One object of the invention is to provide a pump structure which can be actuated pneumatically to avoid electric arcing of electrically operated transfer pumps which are particularly objectionable where the transfer of inflammable fluids is involved.

Another object is to provide a pump structure which is capable of economical manufacture, using available brass tubing for certain parts thereof, and the other parts being designed for coaction therewith to provide an efficient pump structure even though such brass tubes are relatively inexpensive.

Still another object is to provide a pump structure in which a return spring moves a piston in one direction and compressed air moves it in the other direction, a simple valving arrangement being provided for controlling the compressed air so as to automatically reciprocate the piston when compressed air is supplied to the pump.

A further object is to provide an arrangement in which a cylinder may be suspended in a container of liquid or the like and has a piston reciprocable therein, a head being provided at the upper end of the cylinder to which compressed air may be supplied and from which fluid being transferred may flow through a hose or the like.

Still a further object is to provide a foot valve at the lower end of the cylinder and a discharge valve at the upper end with a discharge tube running through the piston for receiving the fluid and transferring it from the foot valve to the discharge valve, the parts being so designed that the piston may reciprocate along the discharge tube without any complications as far as introducing compressed air into the cylinder for reciprocating the piston in one direction is concerned, and likewise with respect to its reciprocation in the opposite direction by a return spring.

An additional object is to provide vent means for avoiding any mixing of air and liquid in such manner that air would find its Way along with the liquid being pumped into the discharge hose.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my pump structure, whereby the objects above contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in detail on the accompanying drawing, wherein:

FIG. 1 is a plan view of my pump structure with certain fittings in the head thereof omitted;

FIG. 2 is a vertical sectional view on the line 2-2 of FIG. 1 showing the complete pump with the parts in the position of the piston just starting to move downwardly, and 7 FIG. 3 is a sectional view on the line 3-3 of FIG.

1 with the parts in the position of the piston just starting to move upwardly.

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On the accompanying drawing I have used the reference numeral 16 to indicate a cylinder which may be stock brass tubing or the like. A head 12 is mounted in the upper end thereof and sealed relative thereto by an O-ring. A mounting sleeve 14 surrounds the upper end of the cylinder 10 and may be secured thereto as by a screw 16, the mounting sleeve being flanged to accommodate a screw cap 18 adapted to be screwed onto a container 20 from which liquid is to be pumped.

In the lower end of the cylinder 1% a foot plug 22 is O-ring-sealed relative to the cylinder and may be positioned relative thereto by a crimp 23 around the tube 10. A nipple 24 extends downwardly from the foot plug 22 on which a flexible intake tube 26 is mounted for extending to the bottom of the container 20.

A foot valve 28 in the form of a rubber disc serves as an intake check valve, being riveted at 39 to a disc 32 resting on the top of the foot plug 22. A piston 34 is slidable in the cylinder 10 and provided with O-rings adjacent its upper and lower ends as illustrated for sealing purposes in relation to the cylinder. A return spring 36 is interposed between the lower end of the piston 34 and the disc 32, thereby serving both as a return spring for the piston and as a means to retain the disc 32 seated on the foot plug 22.

A discharge tube 38 depends from the head 12 and the piston 34 is slidable thereon, 0-rings being provided adjacent the upper and lower ends of the bore of the piston for sealing it in relation to the tube. The tube communicates with a discharge passageway 49 in the head 12 into which a discharge fitting 42 is screwed. The fitting 42 accommodates a discharge hose 44 and a discharge check valve 46 is mounted in the fitting.

A compressed air inlet fitting 48 is mounted in the head 12 and an air inlet passageway 56 of restricted character extends therefrom to the lower surface of the head 12 for discharge of compressed air into the cylinder 10 above the piston 34 as will hereinafter appear. The head 12 is also provided with an exhaust port 52 from its lower surface to its upper surface as shown in FIG. 3.

A pneumatic valve disc 54 is slidable on the tube 38 and provided with a resilient valve disc washer 56 adapted to seat and unseat relative to the lower surface of the head 12 and thereby relative to the exhaust port 52. A valve disc tube 5% depends from the valve disc 54 and enters a piston tube 62, the tubes being provided with an out-turned flange 6t) and an inturned flange 64, respectively, between which a valve spring is mounted.

The piston 34- is provided with inner and outer counterbores 67 and 69, and with a vent 66 while the cylinder 10 has a vent 68 for a purpose which will hereinafter appear.

Practical Operation In the operation of my pump structure, FIG. 2 shows the position of the parts at the beginning of downward motion of the piston 34. Compressed air is entering the fitting 48 and flowing out of the restricted opening 50 and into the upper end of the cylinder 10 for moving the piston downwardiy against the action of the return spring 36. The downward movement of the piston displaces any fluid in the cylinder 16) between the piston and the foot valve 28 (which is closed at this time) upwardly as indicated by the arrow 7 6 through the discharge tube 38,

3 the discharge passageway 46 and the check valve 46 into the discharge hose 44.

Adjacent the lower end of the stroke of the piston 34 the flange 64 engages the spring 65 and compresses it thereby tending to unseat the valve disc washer 5s from the lower end of the head 12 which is resisted by the compressed air inside the upper end of the cylinder 10. Finally the spring is compressed enough, however, to unseat the disc 56 and thus open the exhaust passageway 52 whereupon the disc quickly moves to the wide-open position shown in FIG. 3, thus preventing a point of pressure balance which would cause operating difliculties.

The return spring 36 is now acting to move the piston 34 upwardly against the action of the compressed air still entering through the restricted passageway 50, and is able to so move the piston because of the exhaust port 52 having a considerably larger area than the restricted passageway 50. Thus the air is displaced from above the piston 34 through the exhaust port to atmosphere as illustrated by arrows 72 until the upper end of the piston 34 engages the flange 6t) and recloses the valve disc 56 against the lower end of the head 12 thereby starting repetition of the cycle of operation.

During the upward movement of the piston the foot valve 28 is open as in FIG. 3 and the discharge check valve 46 is closed whereby the piston 34 draws fluid through the intake tube 26 and the open foot valve 23 (arrow 74) into the cylinder below the piston for subsequent displacement on the next downward movement of the piston.

In the event that fluid from below the piston 34 leaks past the lower O-ring seals of the piston it will enter either or both of the counterbores 67 and 69 and through the vents 66 and 68 find its way to the outer surface of the cylinder 10 to return by gravity to the fluid in the container without getting into the upper air section of the pump. Conversely any air that leaks past the upper O-ring seals will find its way into the container 20 and rise to the top of the fluid until its level recedes past the vent 63 without entering the fluid being pumped to the hose 44. To operate in this manner, the counterbore 69 must be longer than the stroke of the piston 34 so that its upper and lower ends do not pass the vent 63.

From the foregoing specification it will be obvious that I have provided a comparatively simple pump structure which may be economically manufactured and involves a minimum of operating parts for automatic valving action. The pump may be operated for transferring fluids from one container to another, as a pressure bleeder of a hydraulic brake system or for other purposes to which it is suited.

Some changes may be made in the construction and arrangement of the parts of my pump structure without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may reasonably be included within their scope.

I claim as my invention:

1. In a pump structure of the character disclosed, a cylinder, a head on one end thereof, a piston reciprocable in said cylinder, a return spring for moving said piston toward said head, a compressed air connection to said head for moving said piston away from said head, a discharge tube supported by said head and extending through said piston, an intake check valve in the end of said cylinder remote from said head for supplying fluid to the intake end of said discharge tube, an outlet check valve communicating with the discharge end of said discharge tube, and means for controlling the supply of compressed air from said air connection to said cylinder and the exhaust of air from said cylinder comprising a valve to coact with said head, said compressed air connection being in constant communication with said cylinder through a restricted opening of said head, an

exhaust port through said head and means responsive to reciprocations of said piston to effect spacing said valve from said head at one limit of movement of said piston as it moves away from said head and engaging said valve with said head at an opposite limit of movement of said piston as it moves toward said head to thereby alternately open and close said exhaust port.

2. A pump structure in accordance with claim 1 wherein said last means comprises a tube extending from said valve, a tube extending from said piston, one of said tubes telescoping in the other and each provided with a flange between which a spring is mounted for compression by movement of said piston against the action of said return spring adjacent the end of the piston movement to snap said valve open.

3. A pump structure in accordance with claim 1 wherein said piston has a counterbore adjacent the cylinder wall longer than the piston stroke and said cylinder has a vent in constant communication therewith and said piston has a counterbore surrounding said discharge tube and a vent between said counterbores.

4. A pump structure in accordance with claim 1 wherein said intake check valve is located in the end of said cylinder remote from said head and said outlet check valve is located in said head.

5. A pump structure in accordance with claim 3 wherein said intake check valve is located in the end of said cylinder remote from said head and said outlet check valve is located in said head.

6. In a pump of the character disclosed, a cylinder, a head on one end thereof, a piston reciprocable in said cylinder, a return spring for moving said piston toward said head, a compressed air connection to said head for moving said piston away from said head, and means for controlling the supply of compressed air from said air connection to said cylinder and the exhaust of air from said cylinder comprising a valve to coact with said head, said compressed air connection being in constant communication with said cylinder through a restricted opening of said head, an exhaust port through said head and means responsive to reciprocations of said piston to effect spacing said valve from said head at one limit of movement of said piston as it moves away from said head and engaging said valve with said head at an opposite limit of movement of said piston as it moves toward said head to thereby alternately open and close said exhaust port, said last means comprises a tube extending from said valve, a tube extending from said piston, one of said tubes telescoping in the other and each provided with a flange between which a spring is mounted for compression by movement of said piston against the action of said return spring adjacent the end of the piston movement to snap said valve open.

7. In a pump of the character disclosed, a cylinder, 21 head on one end thereof, a piston reciprocable in said cylinder, a return spring for moving said piston toward said head, a compressed air connection to said head for moving said piston away from said head, and means for controlling the supply of compressed air from said air connection to said cylinder and the exhaust of air from said cylinder comprising a valve to coact with said head, said compressed air connection being in constant communication with said cylinder through a restricted opening of said head, an exhaust port through said head and means responsive to reciprocations of said piston to effect spacing said valve from said head at one limit of movement of said piston as it moves away from said head and engaging said valve with said head at an opposite limit of movement of said piston as it moves toward said head to thereby alternately open and close said exhaust port, said piston having a counterbore adjacent the cylinder wall longer than the piston stroke and said cylinder having a vent in constant communication therewith.

8. In a pump of the character disclosed, a cylinder, a head on one end thereof, a piston reciprocable in said cylinder, a return spring for moving said piston toward said head, a compressed air connection to said head for moving said piston away from said head, and means for controlling the supply of compressed air from said air connection to said cylinder and the exhaust of air from said cylinder comprising a valve to coact with said head, said compressed air connection being in constant communication with said cylinder through a restricted opening of said head, an exhaust port through said head and means responsive to reciprocations of said piston to effect spacing said valve from said head at one limit of movement of said piston as it moves away from said head and References Cited in the file of this patent UNITED STATES PATENTS Jay Sept. 13, 1921 Clapp V Oct. 23, 1945 

1. IN A PUMP STRUCTURE OF THE CHARACTER DISCLOSED, A CYLINDER, A HEAD ON ONE END THEREOF, A PISTON RECIPROCABLE IN SAID CYLINDER, A RETURN SPRING FOR MOVING SAID PISTON TOWARD SAID HEAD, A COMPRESSED AIR CONNECTION TO SAID HEAD FOR MOVING SAID PISTON AWAY FROM SAID HEAD, A DISCHARGE TUBE SUPPORTED BY SAID HEAD AND EXTENDING THROUGH SAID PISTON, AN INTAKE CHECK VALVE IN THE END OF SAID CYLINDER REMOTE FROM SAID HEAD FOR SUPPLYING FLUID TO THE INTAKE END OF SAID DISCHARGE TUBE, AN OUTLET CHECK VALVE COMMUNICATING WITH THE DISCHARGE END OF SAID DISCHARGE TUBE, AND MEANS FOR CONTROLLING THE SUPPLY OF COMPRESSED AIR FROM SAID AIR CONNECTION TO SAID CYLINDER AND THE EXHAUST OF AIR FROM SAID CYLINDER COMPRISING A VALVE TO COACT WITH SAID HEAD, SAID COMPRESSED AIR CONNECTION BEING IN CONSTANT COMMUNICATION WITH SAID CYLINDER THROUGH A RESTRICTED OPENING OF SAID HEAD, AN EXHAUST PORT THROUGH SAID HEAD AND MEANS RESPONSIVE TO RECIPROCATIONS OF SAID PISTON TO EFFECT SPACING SAID VALVE FROM SAID HEAD AT ONE LIMIT OF MOVEMENT OF SAID PISTON AS IT MOVES AWAY FROM SAID HEAD AND ENGAGING SAID VALVE WITH SAID HEAD AT AN OPPOSITE LIMIT OF MOVEMENT OF SAID PISTON AS IT MOVES TOWARD SAID HEAD TO THEREBY ALTERNATELY OPEN AND CLOSE SAID EXHAUST PORT. 